Problem: Emily ate 3 slices of pizza. William ate 4 slices. If there were initially 9 slices, what fraction of the pizza is remaining?
Explanation: $\text{fraction of pizza eaten} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 7 slices, which leaves 2 out of 9 slices remaining. There is $\dfrac{2}{9}$ of the pizza remaining.